"Marc Andreessen is the co-founder of VC firm Andreessen Horowitz. In the early days of the web, Andreessen co-created Mosaic, the first significant graphical internet browser, and cofounded Netscape, which later sold to AOL for $4.2 billion.

Reid Hoffman co-founded LinkedIn in 2003, and last year he sold the company to Microsoft for more than $26 billion; he now has a seat on the Microsoft board. Along the way, he became one of Silicon Valley’s most influential investors and connectors as a partner at Greylock Partners.